RFEMWSUB1G Module Simple to plug in your RF Explorer unit, compatible with all models Extend band coverage to all popular sub-1Ghz ISM bands, including 315Mhz, 433Mhz, 868Mhz and 915Mhz. Extend internal FLASH and RAM memory for additional capabilities Lifetime free firmware upgrades available, open to community requested features Note this unit does not include RF Generator functionality, only Spectrum Analyzer functionality.